Category: Lepidoptera

Sciencebase readers who also partake of my Imaging Storm website will know already that the moth season has taken off. Night-flying leps are coming to the ultraviolet lure at a rate of knots now; 120 specimens of 60 different species last night (night of 23rd June 2020, logged on the morning of the 24th, many of them NFY (new for the year) and some even NFM (new for me, or as some moth-ers do ‘ave it, NFG, new for garden).

For those who like the stats there have been 20 species NFM in 2020 so far, most of them in the last week. I have no photographed almost 350 moths mostly in the garden, but one or two on field trips (holidays and camping trips) where the opportunity arose. 2000 specimens logged and many photographed so far in 2020.

Metallica are performing out on The Fens – The Brassy Longhorns, Nemophora metallica, feeding and presumably breeding on the Field Scabious growing on the west-facing bank of one of the local fenland drainage ditches known as the Cottenham Lode.

 

TL:DR – There are numerous green moths, they have evolved to mimic leaves and so evade predators through a simple camouflage mechanism. Green Silver-lines is a lovely example of a green moth.

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Some moth names are just so obvious. This member of the Lepidoptera is mostly green and has silvery lines on its wings, hence Green Silver-lines. It’s scientific binomial is a little more cryptic, Pseudoips prasinana.

This is the largest of the resident Lepidoptera of The British Isles: the Privet Hawk-moth, Sphinx ligustri. As its scientific name suggests, this is one of what are commonly known as Sphinx moths in the US and elsewhere. This species can have a wingspan of up to 120 millimetres when its wings are full extended.

At the other extreme of size scale is the Satin Grass-veneer, Crambus perlella, is one of the smaller of our moths, oh not the smallest by a long chalk. It is by definition a micro moth, but the division between micro and macro moths (such as the Privet Hawk-moth above) isn’t, as one might assume, about size but rather the position of the animal on the evolutionary family tree.

As I understand it, what we might term the oldest species, the more “primitive” moths are grouped as the micros. This perhaps bizarrely includes all of the butterflies as micro moths. The macros are then a second evolutionary wave that came millions of years later. Many micro moths around the world are much bigger than the Privet Hawk-moth and many are larger still than some of the much bigger tropical macro moths.

Large Skipper, Ochlodes sylvanus, in flight. My old Canon 6D full-frame digital SLR would never have locked focus quickly enough to get a shot like this. This was taken from about 3 or 4 metres away with a 600mm zoom on a Canon 7D mkii. f/6.3, 1/1600s, ISO 500. I should’ve used a faster shutter speed to freeze the wings as they flap very quickly in this skippy little butterfly.

The 2/3rds cropped sensor of this camera gives the Sigma lens the equivalent “reach” of a 900mm lens, i.e. nominally 50 percent longer focal length. This is an arbitrary fact really, it’s not optical zoom, it’s equivalent to digital zoom on a pocket camera. The photo is also cropped to a much smaller square. Nevertheless, with a similar number of pixels on the smaller sensor and ignoring edge effects, which are negligible except in extremely tightly cropped images, this is far superior to something the 6D would manage.

For those who wonder what the difference is between butterflies and moths, there is none. According to Lepidopterist David Slade asking what is the difference between butterflies and moths is like asking what is the difference between ladybirds and beetles. The butterflies are simply a sub-group of the so-called micro moths (generally considered to be “less evolved” than the macro moths, with a few exceptions), just as any other sub-group within the Lepidoptera (Noctuidae, Pyralidae, Erebidae, Geometridae` is).

The butterflies as a group of moths, however, do differ from all the others, micro and macro in that they lack a mechanical coupling that hooks forewing to hindwing.

In the past, when I’m lecturing a friend at the pub  about the moths I’ve photographed, the terms micro and macro come up and the inevitable question: “Oh, are the micros just the small ones, then?”. As a relative newbie moth-er I’ve struggled to offer a definitive answer. Some moths referred to as micro moths are a lot bigger than some of the smaller macros and some of the macro moths like the “footman” moths and pugs are smaller than some of the micros. Mothing experts have pointed me to papers and articles about identification and one contact suggest that the distinction is in the genitalia…therein lies the clue.

Size isn’t everything, in fact it’s nothing. The micro and macro distinction is nothing, absolutely nothing, to do with size as one might assume given the definition and etymology of those words. No, instead it’s all about evolutionary complexity. The micro moths are essentially the oldest, least evolved part of the Lepidoptera family tree.

All moths and butterflies evolved from a common ancestor about 250 million years ago, same common ancestor as the caddisflies. The micro-moth category includes all the species that evolved from circa 250 to 200 million years ago. The macro-moths are the moths that evolved more recently – from about 125 million years ago – once flowering plants first blossomed. Indeed, nocturnal pollination by moths is more common than daytime pollination by other types of insect.

Butterflies are in evolutionary terms just a sub-group of the micro-moths dating back to perhaps between 110 and 65 million years ago. All butterflies share a common micro-moth ancestor.

There are approximately 160 000 described species of Lepidoptera on the planet still living today, at least 62 000 of those are the micro-moths.

A few more moth species from the actinic lure showing the great diversity of shapes and forms and markings